ES2214718T3 - OPTICAL DEVICES FORMED FROM PROCESSABLE THERMOPLASTIC MATERIALS IN THE FOUNDED STATE THAT HAVE A HIGH INDEX OF REFRACTION. - Google Patents

Abstract

The invention relates to optical devices such as lenses (monofocal and multifocal), progressive lenses, blanks and lens preforms having a specific formula.

Description

Optical devices formed from thermoplastic materials processable in molten state that have a high refractive index

Field of the Invention

This invention generally relates to optical devices such as lenses (monofocal and multifocal), progressive lenses, lens pattern and lens preforms.

Background of the invention

Lenses formed from material Thermoplastics have enjoyed increasing popularity. The Advances in the production of such lenses have included the use of materials that are lighter and that are free of colors undesirable

An attractive and important way to optimize a plastic material lens is by using materials that They have a high refractive index. This allows designers of lenses design finer lenses that have surfaces with greater radii of curvature.

The aromatic thermoplastic materials have been recognized as potential candidates for the manufacture of high refractive index materials for optical applications, particularly in the field of glasses. Polycarbonates aromatics are typical examples for such optical applications and They have a refractive index of about 1.59. However, it know that these materials are subject to chromatic aberration undesirable.

In the bibliography in this regard have been described aromatic polyethers containing half the oxide of triphenylphosphine in the recurring unit. In US Patent Nos. 4,108,837 and 4,175,175 polyethers are shown or suggested aromatics containing the phosphine oxide group. They have tried some work regarding the use of these materials as fibers short range optics and as resistant coatings plasma.

These materials can be synthesized by reacting a variety of bisphenols with 4,4'-bis (fluorophenyl) phenylphosphine oxide (BFPPO) in the presence of a base, such as potassium carbonate, in dipolar aprotic solvents, such as N-methylpyrrolidinone. (NMP) or N, N-dimethylacetamide (DMAC). The synthesis techniques of these compounds are known and many of their physical properties are well documented in the literature. See, for example, CD, Smith, et al . SAMPE Symps Exib. Vol. 35, No. 1, pp 108-22 (1990); RL Holzberlein, et al , Polymer Prepr., Vol. 30, No. 1 p. 293 (1989); DB Priddy, et al , Polymer Prepr., Vol. 34, No. 1, pp. 310-11 (1993); DB Priddy et al , Polymer Prepr. Vol. 33, No. 2, pp. 231-32 (1992); CD Smith, et al ., Polymer Prepr., Vol. 32, No. 1, pp. 93-5 (1991); CD Smith, et al , High Perform. Polymers, Vol. 3, No. 4, pp. 211-29 (1991). A controlled molecular weight can be generated with non-reactive terminal groups, for example, by the use of a monofunctional monomer such as 4-tert-butylphenol.

Summary of the Invention

The present invention relates to devices optics formed from aromatic polyethers containing phosphine oxide and copolymers with non-reactive end groups. These controlled molecular weight polyethers show good mechanical properties, as well as favorable optical properties, such as a refractive index of at least 1.63, a good clarity and a light color. These features are critical for the development of good quality, thin and weight ophthalmic lenses light. The optical devices produced from these materials are also less prone to aberrations chromatic

It is believed that the ends of the chains do not reagents help maintain a stable melt viscosity during the processing operation and to ensure that there is no change some in the melt viscosity as a result of the chain extension or branching during processing, which It also leads to loss of optical properties. The superior thermo-mechanical stability of these materials allows them to be processed at temperatures relatively high without thermal and mechanical degradation.

Detailed description of the invention

Aromatic polyethers containing half phosphine oxide in the backbone of the polymer chain possess the critical properties to be applied successfully in the field of ophthalmic lenses for glasses. The presence of half phosphine oxide in the backbone of the polymer chain contributes to a higher refractive index as well as properties improved thermal and mechanical. These materials show high glass transition temperatures of the order of 200-225 ° C and, therefore, must be processed at high temperatures such as 325-350 ° C. The Mechanical properties of these materials indicate that they are materials tenacious, ductile and at the same time vitreous in conditions environmental and therefore facilitate the generation of thin lenses that have a good impact resistance.

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In the following formula I a polyether is described aromatic containing non-reactive phosphine oxide, properly finalized:

one

The polymer can be formed by reacting BFPPO, bisphenol A and a 4-tert-butylphenol, as shown by then, under the conditions described in example 1.

two

Other homopolymers can be generated using a variety of bisphenols instead of bisphenol A, such as hydroquinone, biphenol, 4,4'-oxidiphenol or bis (4-hydroxyphenyl) sulfone.

A number of copolymers of polyether replacing part of the phosphine oxide monomer with 4,4'-dichlorodiphenylsulfone or 4,4'-difluorbenzophenone. The general structure of Such copolymers can be as follows:

3

where R = -H, 4 5

6

where the molecular weight of the polymer is 15,000 to 25,000, preferably around 20,000

However, morphologies must be maintained. anhydrous

Optical devices manufactured from these materials are optically clear and thinner at their edges than conventional plastic ophthalmic lenses due to at its highest refractive index values.

Example 1 Polymer preparation

In a 4-necked reaction flask provided with argon bubble tube, a mechanical stirrer in head and a Dean-Stark trap connected to a capacitor reflux, 31.43 g (0.1 mol) of oxide was charged 4,4'-bis (fluorophenyl) phenylphosphine (BFPPO) (molecular weight = 314.2706) together with 22.25 g (0.098 mol) of bisphenol A (molecular weight = 228,2902) together with 0.70 g (0.005 moles) of 4-tert-butylphenol (weight molecular = 138,209). The reactants were dissolved in sufficient DMAC to prepare a 30% solution by weight in a DMAC mixture and chlorobenzene (80:20). Chlorobenzene served as a solvent azeotrope former to effectively separate water from the condensation reaction as it formed during polymerization. The reaction was initially maintained at 135-140º for 4 hours until the water separated of condensation completely by distillation. Then the reaction temperature was gradually raised to 165 ° C approximately and remained at that value for 16 more hours. I know then let the reaction product cool to room temperature and filtered to separate inorganic salts and neutralized with glacial acetic acid and was isolated by precipitation in a mixture of Methanol / water stirred rapidly in a high speed mixer. The precipitated polymer was then filtered and dried in an oven. vacuum at approximately 200 ° C overnight after repeatedly washed with methanol to separate any trace of solvent

The preferred range of average molecular weight in number for these polymers is approximately 15,000-25,000 g / mol. Above a molecular weight number average of 25,000 g / mol, the viscosity in molten state It may be too high to get fast processing. By therefore, the polymers have been synthesized with a molecular weight desired of 20000 g / mol. From the bibliography in this regard knows that the length of the polymer chain and, thus, the polymer molecular weight, can be adjusted by controlling the ratio of phosphine oxide to aryl halves used in the synthesis process

Example 2 Lens formation

A single 80mm vision lens was produced diameter with a refractive index of 1.66, a spherical power of -6.00 D and a center thickness of 1.0 mm from the polymer of Example 1 by processing the molten polymer to through an extruder and further formation of a lens from of the hot extrudate in an injection molding machine conventional. The thickness at the edge of said lens is 8.8 mm

A lens with an index correspondingly high, produced from polycarbonate that has an index of 1.58 refraction, under the same set of parameters (that is, center thickness of 1.0 mm, spherical power of -6.00 D and 80 mm of lens diameter) had a thickness at the edge of 10.0 mm.

The above non-limiting examples are offered For illustrative purposes only. The scope of the present invention It is defined only by the following claims.

Claims (10)

1. An ophthalmic lens, a lens pattern or a lens preform comprising a thermoplastic material of formula: 7 where R is hydrogen, 8 9 10 eleven or 0 - 90 moles% ---

 \ melm {} {C} {\ uelm {\ dpara} {\ uelm {O} {}}} 

--- where the molecular weight of the polymer is 15,000 to 25,000. 2. An ophthalmic lens, a lens pattern or a lens preform according to claim 1, wherein the weight The molecular weight of the polymer is approximately 20,000. 3. An ophthalmic lens, a lens pattern or a lens preform according to claim 1 or 2, wherein the Thermoplastic material is of formula: 12 4. An ophthalmic lens, a lens pattern or a lens preform according to any one of claims 1 to 3, consisting of a lens for glasses, a pattern of a lens for glasses or a preform of a lens for glasses. 5. An ophthalmic lens, a lens pattern or a lens preform according to any one of claims 1 to 4, consisting of a lens, a pattern of a lens or a preform of A lens for progressive glasses. 6. An ophthalmic lens, a lens pattern or a lens preform according to any one of claims 1 to 4, consisting of a lens, a lens pattern or a lens preform for bifocals. 7. Procedure to form a lens ophthalmic, a lens pattern or a lens preform, comprising the step of polymerizing a phosphine oxide half and an aryl half cyclic, a bicyclic aryl half or a mixture thereof. 8. Method according to claim 7, in where the aryl half is a mixture of bisphenol and butylphenol. 9. Method according to claim 7 or 8, where the lens is a lens for glasses, a pattern of lenses for glasses or a preform of glasses lenses. 10. Procedure according to any of the claims 7 to 9 for producing a lens for glasses progressive